The present invention relates to apparatus for positioning parts for machining operations and, more particularly, to expansion pins for mounting or locating a workpiece for machining.
Typically to position and hold a component for machining a large vise must be used or a specialized fixture must be built using locating pins in conjunction with other fasteners. Bolts must be completely removed when changing parts or pallets, which can take significant time, particularly for precision machine thread bolts. Also, if a bolt is dropped during mounting or removal, time is taken away from manufacturing.
Often space is limited, and geometry prevents installation. Multiple components must be used to achieve the same results. Other devices are generally far more complex and expensive.
Other expanding pins most often require specialized preparation to install, tedious to install, have no or limited ability to be modified to hold smaller parts, are multi-piece assemblies, difficult to manufacture and prone to malfunction due to debris entry, rust and contamination.
This device works equally well as a threaded in insert with controlled fit counter bore, press fit or controlled fit bore, a taper fit etc. allowing the device to be used in many standard fixtures without modification the fixture, for example, tombstone fixtures mounted on horizontal machining centers. The device itself can be furnished as an oversize mandrel that can be machined to less than 50% of its original diameter. The device holds and can position in the X, Y, Z, directions and also resists rotation along the C/L Axis.
As can be seen, there is a need for a self-contained expansion pin that can remain affixed to a work station while permitting the easy switching of a workpiece.